/*
 MIT License
 
 Copyright © 2017 Nathan Tannar.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
*/

import UIKit

public struct Style<View: UIView> {
    
    public let style: (View) -> Void
    
    public init(style: @escaping (View) -> Void) {
        self.style = style
    }
    
    /// Applies self to the view.
    public func apply(to view: View) {
        style(view)
    }
    
    /// Style that does nothing (keeps the default/native style).
    public static var native: Style<View> {
        return Style { _ in }
    }
}

extension UIView {
    
    /// For example: `let nameLabel = UILabel(style: Stylesheet.Profile.name)`.
    public convenience init<V>(style: Style<V>) {
        self.init(frame: .zero)
        apply(style)
    }
    
    public convenience init<V>(style: Style<V>, override: @escaping (V) -> Void) {
        self.init(frame: .zero)
        apply(style.modifying(override))
    }
    
    /// Applies the given style to self.
    public func apply<V>(_ style: Style<V>) {
        guard let view = self as? V else {
            print("💥 Could not apply style for \(V.self) to \(type(of: self))")
            return
        }
        style.apply(to: view)
    }
    
    
    /// Returns self with the style applied. For example: `let nameLabel = UILabel().styled(with: Stylesheet.Profile.name)`.
    public func styled<V>(with style: Style<V>) -> Self {
        guard let view = self as? V else {
            print("💥 Could not apply style for \(V.self) to \(type(of: self))")
            return self
        }
        style.apply(to: view)
        return self
    }
}

extension Style {
    
    /// Returns current style modified by the given closure.
    public func modifying(_ other: @escaping (View) -> Void) -> Style {
        return Style {
            self.apply(to: $0)
            other($0)
        }
    }
}
